What do I picture? 2D pieces, to be honest. Computer chess is just so prevalent. I picture what I'd call "USCF style" [1] because that's what they'd use in the Chess Life magazine to annotate games. I also picture the "old style" pieces [2], used in other periodicals & some books (especially puzzles).

I bet a lot of people picture the default set on Chess dot com. I find it very hard to adjust to new sets, for whatever reason.

As far as real pieces, I picture plastic pieces & vinyl board. Either what I'd call the "triple-weighted set" [3] (my favorite), the plastic "Dreuke set" [4], or the "basic USCF set" [5].

I had no idea there were so many variations, especially in the last 100 years. Most I've never seen before. I still dislike the real abstract/bauhaus style but there's a lot of artistry in the sets.

[1] on lichess, it's called "companion"

[2] on lichess, it's called "leipzig"

[3] https://www.chessset.com/collections/weighted-chess-pieces-h...

[4] Player's Choice, like https://www.wholesalechess.com/reproduction-of-the-drueke-pl...

[5] https://www.uscfsales.com/single-weighted-regulation-plastic...